Transistor having compensation zones enabling a low on-resistance and a high reverse voltage

ABSTRACT

A semiconductor component includes a semiconductor body having a substrate of a first conduction type and a first layer of a second conduction type that is located above the substrate. A channel zone of the first conduction type is formed in the first layer. A first terminal zone of the second conduction type is configured adjacent the channel zone. A second terminal zone of the first conduction type is formed in the first layer. Compensation zones of the first conduction type are formed in the first layer. A second layer of the second conduction type is configured between the substrate and the compensation zones.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor component, inparticular a field-effect-controllable transistor.

DE 198 28 191 C1 discloses a lateral high-voltage transistor having, onan n-conducting substrate, an epitaxial layer in which source and drainzones and also a channel zone surrounding the source zone are formed.Trenches are provided in the epitaxial layer. The sidewalls of thesetrenches are heavily doped with a complementary dopant with respect tothe rest of the epitaxial layer. A conductive channel in the channelzone can be controlled by means of a gate electrode insulated from thechannel zone.

When a source-drain voltage is applied, a space charge zone propagatesin this transistor—if no gate-source voltage is applied—proceeding fromthe source zone, and as the voltage rises, the space charge zonegradually reaches the complementarily doped sidewalls of the trenches inthe direction of the drain zone. Where the space charge zone propagates,free charge carriers of the doped sidewalls of the trenches and freecharge carriers of the surrounding epitaxial layer mutually compensateone another. In these regions in which the free charge carriers mutuallycompensate one another, a high breakdown voltage results for lack offree charge carriers. The reverse voltage of the transistor can be setby means of the doping of the trenches, the epitaxial layer preferablybeing highly doped, as a result of which the transistor has a low onresistance when the gate is driven.

Such transistors having a low on resistance but a high reverse voltageare currently available only as discrete components, that is to say onlythe transistor is realized in a semiconductor body. However, for manyapplications, for example for switching loads, it is desirable tointegrate a transistor as a switching element and its associated drivecircuit, for example using CMOS technology, in a single semiconductorbody.

SUMMARY OF THE INVENTION

The semiconductor component according to the invention has asemiconductor body with a substrate of a first conduction type and,situated above the latter, a first layer of a second conduction type. Inthe layer of the second conduction type there is formed a channel zoneof the first conduction type with a first terminal zone of the secondconduction type arranged adjacent to it. Furthermore, a second terminalzone of the second conduction type is formed in the second layer. In atransistor, the first terminal zone forms the source zone and the secondterminal zone forms the drain zone. The source zone is surrounded in thesecond layer by the channel zone, in which a conductive channel can formas a result of the application of a drive potential to a controlelectrode or gate electrode which is arranged in a manner insulated fromthe channel zone.

In order that the first layer can be highly doped for the purpose ofachieving a low on resistance, and, on the other hand, in order that ahigh reverse voltage is achieved, compensation zones of the firstconduction type are provided in the first layer, a second layer of thesecond conduction type being formed between these compensation zones andthe substrate of the first conduction type, said second layer preferablybeing doped more lightly than the first layer.

In integrated circuits, the substrate is usually at a reference-groundpotential. The second layer then prevents charge carriers from passinginto the substrate when a high potential is applied to one of theterminal zones; in the substrate said charge carriers could pass toother circuit components in the semiconductor body, for example to adrive circuit, and interfere with their functioning. In the event of alarge potential difference between one of the terminal zones and thesubstrate, the second layer is depleted on account of the space chargezone which then forms, that is to say the free charge carriers in thesecond layer and free charge carriers of the substrate and/of thecompensation zones mutually compensate one another. The second layerthen forms a potential barrier for free charge carriers of the firstconduction type between the first layer and the substrate.

One embodiment of the invention provides a boundary zone which extendsin the vertical direction of the semiconductor body. This boundary zonepreferably reaches in the lower region of the semiconductor body as faras the substrate and extends in the upper region of the semiconductorbody as far as the channel zone or is arranged offset with respect tothe channel zone in the lateral direction of the semiconductor body andreaches as far as a first surface of the semiconductor body. Theboundary zone of the first conduction type, which is thus dopedcomplementarily with respect to the first layer, bounds thesemiconductor component according to the invention in the lateraldirection of the semiconductor body. A charge carrier exchange in thelateral direction is prevented by the boundary zone, as a result ofwhich further semiconductor circuits, for example drive circuits usingCMOS technology, can be realized beyond said boundary zone, the drivecircuit and the semiconductor component according to the invention notmutually interfering with one another.

One embodiment of the invention provides for the compensation zones inthe first layer to extend in a pillar-shaped manner in the verticaldirection of the semiconductor body, in which case, according to afurther embodiment, at least some of the compensation zones adjoin thechannel zone. In transistors, the source zone as first terminal zone andthe channel zone are usually short-circuited, so that the compensationzones adjoining the channel zone are at the same potential as the firstterminal zone.

According to a further embodiment of the invention, the compensationzones are of spherical design and arranged such that they aredistributed in the first layer of the second conduction type.

A further embodiment provides for the first layer of the secondconduction type to be weakly doped and for more heavily doped secondcompensation zones of the second conduction type to be formed adjacentto the compensation zones, which, in particular, are of pillar-shapeddesign. When a high voltage is applied between the first and secondterminal zones, the compensation zones of the first conduction type andthe respectively adjacent second compensation zones of the secondconduction type mutually deplete one another, that is to say the freecharge carriers of the compensation zone of the first conduction typeand the free charge carriers of the second compensation zone of thesecond conduction type mutually compensate one another.

One embodiment of the semiconductor component according to the inventionprovides for the second terminal zone to be formed in a well-like mannerin the region of the first surface of the semiconductor body or thefirst layer. In this exemplary embodiment, the charge carriers movebetween the first and second terminal zones essentially in the lateraldirection of the semiconductor body. A further embodiment provides forthe second terminal zone to extend in the vertical direction of thesemiconductor body as far as the second layer and to run in the regionof the second layer in the lateral direction of the semiconductor bodybelow the first terminal zone. In this embodiment, in which the lateralsection of the highly doped second terminal zone runs in a manner buriedin the semiconductor body and can be contact-connected by means of thevertical section at the first surface of the semiconductor body, thecharge carriers move essentially in the vertical direction of thesemiconductor body.

A further embodiment provides for vertical sections of the secondterminal zone and the laterally running section of the second terminalzone to enclose the first terminal zones and at least some of thecompensation zones in a well-like manner.

In accordance with an added feature of the invention, the first layerhas a number of dopant atoms of the first conduction type and a numberof dopant atoms of the second conduction type that are approximatelyidentical.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of a first exemplary embodiment of asemiconductor component;

FIG. 2 is a plan view of an embodiment of a semiconductor component withelongate first terminal zones;

FIG. 3 is a plan view of an embodiment of a semiconductor component withan annularly closed first terminal zone;

FIG. 4 is a cross sectional view of another exemplary embodiment of asemiconductor component;

FIG. 5 is a cross sectional view of another exemplary embodiment of asemiconductor component with a plurality of first terminal zones andcompensation zones running in a pillar-shaped manner;

FIG. 6 is a cross sectional view of another exemplary embodiment of asemiconductor component with a plurality of first terminal zones andcompensation zones of spherical design;

FIG. 7 is a cross sectional view of another exemplary embodiment of asemiconductor component with a plurality of first terminal zones andwith first compensation zones adjacent second compensation zones; and

FIG. 8 is a cross sectional view of another exemplary embodiment of asemiconductor component with a plurality of first terminal zones andwith a second terminal zone surrounding the first terminal zones in awell-like manner.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the figures, unless specified otherwise, identical reference symbolsdesignate identical sections and zones with the same meaning.

FIG. 1 shows a semiconductor component according to the invention,designed as a MOS transistor, in a lateral sectional illustration, FIG.2 showing a section through the semiconductor component according toFIG. 1 along the sectional plane A—A′ in the case of a first embodiment,and FIG. 3 showing the semiconductor component according to FIG. 1 in aplan view of the sectional plane A—A′ in the case of a secondembodiment. The exemplary embodiments illustrated in FIGS. 2 and 3 donot differ in their side view, which is shown for both exemplaryembodiments in FIG. 1.

The MOS transistor according to the invention has a semiconductor body20 with a weakly p-doped substrate 22 and, situated above the latter, ann-doped first layer 24. A p-doped channel zone 50 is introduced in awell-like manner in the first layer 24, proceeding from a first surface201, a heavily n-doped first terminal zone 40 being formed in awell-like manner in said channel zone. In this case, the first terminalzone 40 forms the source zone of the MOS transistor. In the n-dopedfirst layer 24, a heavily n-doped second terminal zone 60 is introducedspaced apart from the channel zone 50 in the lateral direction of thesemiconductor body 20, which terminal zone is likewise formed in awell-like manner proceeding from the first surface 201 in the exemplaryembodiment according to FIG. 1. The second terminal zone 60 forms thedrain zone of the MOS transistor. The drain zone 60 is contact-connectedby means of a drain electrode 62 which is arranged on the first surface201 and forms a drain terminal of the MOS transistor. In a correspondingmanner, the source zone 40 is contact-connected by means of a sourceelectrode 52 which short-circuits the source zone 40 and the channelzone 50 and which forms the source terminal S of the MOS transistor.

For driving the MOS transistor, provision is made of a gate electrode 70above the channel zone 50, which is insulated from the semiconductorbody 20 by means of an insulation layer 72 and which forms a gateterminal of the MOS transistor.

FIG. 1 shows, in cross section, two source zones 40 and channel zones50, in each case in the lateral direction of the semiconductor body 20on the left and right beside the drain zone 60. These source zones 40are connected to one another and, as is illustrated in FIG. 2, may bedesigned as elongate strips in the semiconductor body 20 between which alikewise elongate drain zone 60 is formed. The elongate source zones andthe elongate drain zone can extend as far as edges or edge regions ofthe semiconductor body. The channel zone 50 and the source zone 40 canalso enclose the drain zone 60 annularly as is illustrated in FIG. 3.FIG. 1 illustrates a cross section both through the semiconductorcomponent according to the invention according to FIG. 2 and through thesemiconductor component according to the invention according to FIG. 3.

P-doped compensation zones 30 are formed in the n-doped layer 24 and, inthe exemplary embodiment according to FIG. 1, extend in a pillar-shapedmanner in the vertical direction of the semiconductor body 20. The crosssection of these pillar shaped compensation zones 30 is circular in theexemplary embodiments according to FIGS. 2 and 3, but this cross sectioncan assume virtually any other geometric shapes and be, for example,rectangular, square or octagonal.

In the exemplary embodiment according to FIG. 1, the pillar-shapedcompensation zones 30 start at the level of the first surface 201 andextend in the vertical direction as far as a second n-conducting layer26 formed between the compensation zones 30 and the substrate 22. Inthis case, this second n-conducting layer 26 is preferably doped moreweakly than the first n-conducting layer 24.

Furthermore, a p-doped layer 32 is formed below the first surface 201 ofthe semiconductor body 20, which layer preferably reaches as far as thechannel zone 50 and connects the compensation zones 30 to one another.The p-doped layer 32 preferably does not reach as far as the secondterminal zone 60. Equally, a compensation zone 30A formed below thedrain zone 60 does not reach as far as the drain zone 60.

The region of the first layer 24 in which the compensation zones 30 areformed forms the drift path of the MOS transistor. The MOS transistor orits drift path is bounded in the lateral direction of the semiconductorbody by a p-doped boundary zone 80 which, in the exemplary embodimentaccording to FIG. 1, extends in the vertical direction of thesemiconductor body proceeding from the channel zone 50 as far as thesubstrate 22. In this case, like the source zone 40 in FIG. 2, theboundary zone 80 can run below the source zone in an elongate manner asfar as the edges of the semiconductor body 20 or, in accordance with thesource zone 40 in FIG. 3, it can annularly surround the drift path.

The boundary zone 80, which is preferably doped more highly than thep-doped substrate 22, forms a pn junction with the first layer 24 andprevents n-type charge carriers from passing through the boundary zone80 into n-doped zones 124 of adjacent components, or adjacentsemiconductor circuits, which are represented by way of example in FIG.1 by two CMOS transistors T1, T2 and a terminal for supply potential +U.Such a drive circuit might be, for example, a drive circuit for the MOStransistor according to the invention illustrated on the right in FIG.1, which drive circuit is realized with the MOS transistor in the samesemiconductor body.

Typical doping concentrations of the individual zones of thesemiconductor component according to FIG. 1 are specified below by wayof example:

Substrate 22: Volume doping 10¹⁴-10¹⁵ cm⁻³ n-doped zone 124: Volumedoping 10¹⁵-10¹⁶ cm⁻³ Drain zone 60: Volume doping 10¹⁸-10²⁰ cm⁻³Compensation zones 30: Area doping 10¹² cm⁻² Drift path 24: Area doping10¹² cm⁻² Second layer 26: Area doping 10¹² cm⁻² Zone 32: Area doping<10¹² cm⁻²

This MOS transistor has a low on resistance and a high breakdownvoltage, the second n-conducting layer 26 preventing charge carriersfrom passing from the drift zone of the MOS transistor into thesubstrate 22, as is explained below.

If, in the MOS transistor according to the invention, a positive voltageis applied between the gate terminal G and the source terminal S, then aconductive channel forms in the channel zone 50 below the gate electrode72. If a positive voltage is applied between the drain electrode D andthe source electrode S, a charge carrier current flows in the lateraldirection of the semiconductor body 20 through the drift path betweenthe source zone 40 and the drain zone 60. The drain-source voltage isrepresented as voltage +U_(D) in FIG. 1, it being assumed that thesource electrode is at a reference-ground potential of the circuit, inparticular ground. The on resistance R_(on) of the MOS transistor islower, the higher the doping of the first layer 24 with n-type chargecarriers.

If the MOS transistor is in the off state, that is to say there is nodrive potential at its gate electrode, then when a drain-source voltageis applied, a space charge zone propagates proceeding from the sourcezone 40 or the channel zone 50 in the drift path in the direction of thedrain zone 60. This space charge zone advances in the direction of thedrain zone 60 as the drain-source voltage increases. If the space chargezone reaches a compensation zone 30, then the compensation zone 30assumes the potential of the space charge zone upon reaching thecompensation zone 30. Free p-type charge carriers (holes) of thiscompensation zone 30 and free n-type charge carriers (electrons) fromthe regions of the drift path which surround the respective compensationzone mutually compensate one another. The number of free charge carriersthereby decreases in the drift path as the reverse voltage increases, oras the space charge zone extends further. The compensation of the freecharge carriers means that the MOS transistor has a high reversevoltage.

In semiconductor bodies in which a plurality of semiconductor componentsare realized, the substrate 22 is usually at reference-ground potential.In the exemplary embodiment according to FIG. 1 the substrate 22 can becontact-connected by means of an electrically conductive layer 90, forexample a metalization layer applied on the substrate. The voltagebetween the drain terminal 60 and the substrate 22 then corresponds tothe drain-source voltage of the MOS transistor. As the drain potential+U_(D) increases, a space charge zone propagates upward proceeding fromthe substrate 22, as a result of which the second n-conducting layer isdepleted, that is to say the free n-type charge carriers of the secondlayer 26 and holes in the surrounding substrate 22 or the upwardlyadjoining compensation zones 30 mutually compensate one another. Thesecond layer 26, which is preferably doped in such a way that it can becompletely depleted, thus forms a potential barrier for free chargecarriers of the drift path and prevents said free charge carriers frompassing into the substrate 22, where they could propagate unimpeded andinterfere with the functioning of other semiconductor componentsintegrated in the semiconductor body 20.

The dopings of the compensation zones 30, of the drift path 24 and ofthe second layer 26 are preferably co-ordinated with one another in sucha way that the number of p-type charge carriers approximatelycorresponds to the number of n-type charge carriers, so that at themaximum possible reverse voltage, when the space charge zone reaches thedrain zone 60 proceeding from the source zone 40, the compensation zones30, the drift path 24 and the second layer 26 are completely depleted,that is to say no free charge carriers are present. The breakdownvoltage then corresponds to the breakdown voltage of an undoped driftpath 24.

The MOS transistor according to the invention, with the source zone 40,the channel zone 50 surrounding the source zone, the drain zone 60, thedrift path 24 with the compensation zones 30, the boundary zone 80, ann-conducting layer 26 between the compensation zones 30 and with thesubstrate 22, can be integrated together with further semiconductorcomponents in a semiconductor body. Consequently, a MOS transistor aspower switch with a low on resistance and a high reverse voltage can beintegrated together with its drive circuit in a semiconductor body or achip in a space-saving manner.

FIG. 4 shows a further exemplary embodiment of a semiconductor componentaccording to the invention in cross section. Whereas in the exemplaryembodiment according to FIG. 1 the p-conducting boundary zone 80 extendsas far as the substrate 22 proceeding from the channel zone 50 in thevertical direction of the semiconductor body 20, in the exemplaryembodiment according to FIG. 4 the boundary zone 80 is arranged suchthat it is spaced apart from the channel zone 50 in the lateraldirection and extends from the first surface 201 in the verticaldirection of the semiconductor body 20 as far as the substrate 22.Pillar-like compensation zones 30B, 30C, 30D are formed in then-conducting layer 24 between the channel zone 50 and the boundary zone80, said compensation zones extending in the vertical direction of thesemiconductor body 20 from the first surface 201 as far as the secondn-conducting layer 26. Unlike the compensation zones 30 between thechannel zone 50 and the drain zone 60, the compensation zones 30B, 30C,30D between the channel zone 50 and the boundary zone 80 are notconnected to one another by a p-conducting layer 32. Consequently, thecompensation zones 30B, 30C, 30D between the channel zone 50 and theboundary zone 80 are designed in a “floating” manner in the second layer24, that is to say they are not at a defined potential and assume thepotential of a space charge zone which extends as far as thecompensation zones 30 when the semiconductor component is in the offstate. Discharging of the compensation zones 30B, 30C, 30D when the MOStransistor is switched on again can be effected by thermal chargecarriers.

The compensation zones 30B, 30C, 30D between the channel zone 50 and theboundary zone 80 increase the breakdown voltage between the MOStransistor, which is formed within a well, formed by the boundary zone80 and the n-conducting second layer 26, and adjacent semiconductorcomponents, which are not illustrated in FIG. 4 for reasons of clarity.

The sectional illustration according to FIG. 4 furthermore shows fieldplates 90, 91, 92, 93, 94, which are arranged on the first surface 201in a manner insulated from the semiconductor body 20 by an insulationlayer 74. These field plates influence, in a known manner, the fieldline profile within and outside the semiconductor body and prevent avoltage breakdown in the edge regions of the MOS transistor or edgesthereof. In this case, a first field plate 90 running obliquely upwardis connected to the boundary zone 80, a second and third field plate 91,92 are connected to the source terminal S and a fourth and fifth fieldplate 93, 94 are connected to the drain terminal D.

FIG. 5 shows a further exemplary embodiment of a semiconductor componentaccording to the invention, designed as a MOS transistor, in a lateralsectional illustration. The semiconductor component according to thisexemplary embodiment has a plurality of source zones 40A, 40B, 40C andrespective channel zones 50A, 50B, 50C surrounding the latter, thesource zones 40A, 40B, 40C and the channel zones 50A, 50B, 50C beingconnected to a common source electrode 52,S. The source zones 40A, 40B,40C are, in particular, of annular design, FIG. 5 showing a sectionthrough the center of these annular source zones.

In the component according to FIG. 5 gate electrodes 70A, 70B, 70C, 70Dare arranged on the semiconductor body in a manner insulated byinsulation layers 72A, 72B, 72C, 72D and are connected to a common gateelectrode G. The gate electrodes 70A, 70B, 70C, 70D illustrated in FIG.5 may be, in particular, constituent parts of a single gate electrode ofgrid-like design, in which case the source zones 40A, 40B, 40C, 40D withthe channel zones 50A, 50B, 50C are arranged below cutouts of the gridand, in the cutouts of the grids, the source zones are contact-connectedby means of the source electrode 52.

Compensation zones 30 are formed in the first n-conducting layer 24arranged above the substrate 22, some of these compensation zonesadjoining the channel zones 50A, 50B, 50C and extending in a pillar-likemanner in the vertical direction of the semiconductor body 20. Othercompensation zones 30E are formed between the channel zones 50A, 50C andthe boundary zones 80, the boundary zones extending from the firstsurface 201 of the semiconductor body 20 as far as the substrate 22. Inthe exemplary embodiment according to FIG. 5, the drain zone 60 extendsproceeding from the first surface 201 in the vertical direction as faras the n-doped second layer 26 formed between the substrate 22 and thefirst n-conducting layer 24. The drain zone 60 additionally extends inthe lateral direction of the semiconductor body in the region of thesecond layer 26 below the first terminal zones 40A, 40B, 40C. Whereas inthe exemplary embodiments according to FIGS. 1 to 4 the charge carriertransport runs between the source zones and the drain zones essentiallyin the lateral direction of the semiconductor body 20, the chargecarriers in the exemplary embodiment according to FIG. 5 propagate, withthe gate electrode G being driven, in the vertical direction of thesemiconductor body between the source zones 40A, 40B, 40C and thelaterally running section of the drain zone 60. In the exemplaryembodiment according to FIG. 5, the volume of the drift path can bebetter utilized as a result of the larger area of the drain zone 60, atwhich charge carriers can be taken up from the drift path, and thelarger channel area resulting from the provision of a plurality ofsource zones 40A, 40B, 40C and channel zones 50A, 50B, 50C. In otherwords, the MOS transistor according to FIG. 5 has a highercurrent-carrying capacity than the MOS transistors according to FIGS. 1to 4. In the exemplary embodiment according to FIG. 5, the second layer26 and the laterally running section of the drain zone 60 form apotential barrier for charge carriers from the drift path into thesubstrate 22.

The drain zone 60 has a first section 100 extending vertically to thesecond layer 26 and a second section 102 extending laterally at thelevel of the second layer 26.

FIG. 6 shows a further exemplary embodiment of a semiconductor componentaccording to the invention, which differs from that illustrated in FIG.5 by virtue of the fact that the compensation zones 30 in the firstn-conducting layer 24 are of spherical design and are arranged spacedapart from the channel zones 50A, 50B, 50C, 50D.

In the exemplary embodiment according to FIG. 7, the n-conducting layer24 is weakly n-doped, second n-conducting compensation zones 25 beingformed beside the p-conducting compensation zones 30, the respectivelyadjacent compensation zones 30, 25 mutually depleting one another when aspace charge zone propagates in the first layer 24, in order thus tobring about a high breakdown voltage of the semiconductor component. Inthe exemplary embodiment according to FIG. 7, some of the p-conductingcompensation zones 30 are connected to the channel zones 50A, 50B, 50Cand are thus at source potential.

FIG. 8 shows a further exemplary embodiment of a semiconductor componentaccording to the invention, in which the drain zone 60 is of U-shapeddesign in cross section and encloses the first terminal zones 40A, 40B,40C and the channel zones 50A, 50B, 50C and some of the compensationzones 30. The drain zone 60 is preferably in the form of a well andencloses the first terminal zones 40A, 40B, 40C and the channel zones50A, 50B, 50C and some of the compensation zones 30 on all sides in thelateral direction of the semiconductor body 20.

LIST OF REFERENCE SYMBOLS

20 Semiconductor body

22 Substrate

24 First n-conducting layer

26 Second n-conducting layer

30, 30A Compensation zone

32 p-conducting layer

40 Source zone

50, 50A, 50B, 50C Channel zone

52 Source electrode

60 Drain zone

62 Drain electrode

70 Gate electrode

70A, 70B, 70C, 70D Gate electrodes

72 Insulation layer

72A, 72B, 72C, 72D Insulation layers

80 Boundary zone

90 Metalization layer

90, 91, 92, 93, 94 Field plates

95 Field plate

124 n-conducting layer

126 n-conducting layer

201 First surface of the semiconductor body

T1, T2 CMOS transistors

S Source terminal

G Gate terminal

D Drain terminal

+U_(D) Drain potential

n n-doped zone

p p-doped zone

I claim:
 1. A semiconductor component comprising: a semiconductor bodyhaving a substrate of a first conduction type and first layer of asecond conduction type located above said substrate: a channel zone ofsaid first conduction type formed in said first layer; a first terminalzone of said second conduction type configured adjacent said channelzone; a second terminal zone of said first conduction type formed insaid first layer; compensation zones of said first conduction typeformed in said first layer; and a second layer of said second conductiontype configured between said substrate and said compensation zones. 2.The semiconductor component according to claim 1, comprising: a boundaryzone of said first conduction type extending vertically in said firstlayer towards said semiconductor body.
 3. The semiconductor componentaccording to claim 2, wherein said boundary zone extends from saidchannel zone to said substrate.
 4. The semiconductor component accordingto claim 2, wherein said boundary zone is laterally spaced away fromsaid channel zone.
 5. The semiconductor component according to claim 4,wherein: said semiconductor body has a first surface; and said boundaryzone extends from said first surface of said semiconductor body to saidsubstrate.
 6. The semiconductor component according to claim 1, whereinsaid compensation zones have a pillar-shaped design.
 7. Thesemiconductor component according to claim 6, wherein at least same ofsaid compensation zones adjoin said channel zone.
 8. The semiconductorcomponent according to claim 1, wherein said compensation zones have aspherical design.
 9. The semiconductor component according to claim 1,wherein: said compensation zones define first compensation zones: saidfirst layer has second compensation zones of said second conduction typeformed therein; said second compensation zones are adjacent said firstcompensation zones; and said second compensation zones are doped moreheavily than said second layer.
 10. The semiconductor componentaccording to claim 1, wherein said boundary zone is doped more heavilythan said substrate.
 11. The semiconductor component according to claim1, wherein: said second terminal zone has a first section extendingvertically to said second layer; and said second layer laterally extendsat a level; said second terminal zone has a second section extendinglaterally at said level of said second layer.
 12. The semiconductorcomponent according to claim 11, wherein said first section and saidsecond section of said second terminal zone form a well-like structureenclosing said first terminal zone and at least some of saidcompensation zones.
 13. The semiconductor component according to claim1, wherein: said second terminal zone has a first section extendingvertically to said second layer; and said second terminal zone has asecond section extending laterally near said second layer.
 14. Thesemiconductor component according to claim 13, wherein said firstsection and said second section of said second terminal zone form awell-like structure enclosing said first terminal zone and at least someof said compensation zones.
 15. The semiconductor component according toclaim 1, wherein said first layer has a number of dopant atoms of saidfirst conduction type and a number of dopant atoms of said secondconduction type that are approximately identical.